Prior art inspection systems have been provided for inspecting various components in quality control operations. In the manufacture of electronic components, optical inspection systems are often used to provide automated visual inspection of the packaging for electronic components. Various parameters are inspected such as whether the appropriate markings are correctly placed upon the component packages, whether the leads and the cases of the components are of the correct configuration, and whether the leads are manufactured and then formed in correct alignment. Lead alignment measurements include lead pitch, lead displacement, lead offset, lead span, lead standoff and lead coplanarity. High speed automatic inspection systems capable of high throughput are required to provide adequate quality control on an economic basis. As the complexity of electronic component packages have increased, the need for accurate automatic inspection systems has also increased.
One type of electronic component currently being manufactured in large volumes are quad flatpack components for flatpack assembly operations. Such quad flatpack components typically have a large number of leads that extend from all four sides of a rectangular or square shaped component package. Current lead spacings are approximately 0.016 inches. Components for surface mounting operations are typically inspected for lead alignment in order to assure the correct lead spacing and coplanarity between the lower surfaces of the leads which are directly mounted to surface mount circuit boards. Improper lead alignment may result in incorrect mounting of components to circuit boards, and lower production assembly yield rates.
Some prior art vision inspection systems have been provided for inspecting quad flatpack systems. Often, five to eight cameras are utilized for inspecting the components from various angles. When a large number of cameras are utilized for optical inspection purposes, each of the cameras has to be aligned and then corresponding images from various frames from the different cameras coordinated such that data may be processed for determining whether the lead alignment and packaging components are manufactured within acceptable limits. Further, prior art vision inspection systems typically stationarily position the components above a region proximate to the vision inspection system at which the various recording cameras are focused. However, having to stationarily position components above a particular position in relation to the vision inspection system requires stoppage of components thereabove and increases the time required for inspection.